Process of making sodium oxid.



Patented June 23, 1903,

AUGUSTUS BISOHLER, OF BASLE, SWITZERLAND, ASSIGNOR TO THE FIRM OF BASLECHEMICAL WORKS, OF BASLE, SWITZERLAND.

PROCESS OF MAKING SODIUM O XID.

SPECIFICATION forming part of Letters Patent No. 731,746, dated June 23,1903.

' 7 Application filed October 25,1902. Serial No. 128,821. (Nospecimens.)

To all whom, it may concern:

Be it known that I, AUGUSTUS BIsoHLnR,

chemist anddoctor of philosophy, a subject of theEmperor of Russia,andaresident ofBasle, Switzerland, have invented a new Process for theManufacture of Sodium Oxid,of which the following is an exact, clear,and complete specification;

Holt and Sims are said to have obtained so- 10 dium oxid by letting alimited volume of oxygen or air act upon sodium heated to less than 180centigrade. (Journal of the Chem. 800., 1894., page 440.) By repeatingthese experiments I was able to observe that when pass- I :5 ing airover sodium heated to less than 180 centigrade the escaping air after acertain time'ceases to carry oft particles of sodium or of sodiumperoxid. If after this time a weighed part of the reaction mass, whichpresents a grayish-white appearance, was dissolved in water andtriturated with acids figures of more or less accordance with sodiumoxid were obtained. In reality, however, the product ofoxidation alwaysconsisted of a mixture of sodium peroxid and metallic so dium. Accordingto my observations sodium peroxid is always formed when oxidizing sodiumwith air oxygen at not too high a temperature. If, on the contrary, theoxidation is performed at a very high temperature with a limitedquantity of oxygen or air, oxid of sodium is obtained. It is accordingto this method that Beketow first produced pure sodium oxid. (Bert'chteder Deazfschen Chemischen Gesellschaft, XVI, 1854..) But even apart fromthe fact that Beketow at last was obliged always to heat with blast,whereby according to my experience when heatingin castiron vessels theiron begins to replace the so- 0 dium of the sodium oxid, his essays didnot always produce the desired result, as he was obliged to fix thequantity of oxygen exactly in proportion to the sodium employed. 1 havenow found that sodium oxid may easily be obtained by heating equivalentquantities of peroxid of sodium and sodium. For this purpose sodium isfirst oxidized completely or incompletely to sodium peroxid and thenheated with the calculated quantity of sodium to over400 centigrade.This may be performed either by adding the sodium, little by little,

to the peroxid, heated to over 400 centie grade, or in the opposite Wayby slowly adding the peroxid to the heated sodium. I have further foundthat for the reduction of the sodium peroxid with sodium an additionof afew per cent. of caustic soda or caustic potash is of advantage, as thereaction is then more easily accomplished.

Example-Pr0duction 0fsodt'umper0a2id.- Five kilos of sodium are firstheated in a castiron vessel to about 200 centigrade, whereupon a currentof air free from carbonic anhydrid and containing traces of moisture ispassed over the sodium. As soon as the eur- 5 rent of air carries offhardly any more sodium or sodium peroxid the temperature is slowlyraised to about 400 centigrade. The oxidation proceeds more or lessquickly according to the strength of the current of air. The reactionproducta yellow loose powder-is well mixed and titrated. If all thesodium is oxidized, the peroxid is reduced with five kilos of sodium inthe manner described'hereinafter; but should the peroxid still containsodium a proportionately smaller quantity of sodium is used for thereaction.

Production of sodium oxid.-Jivekilos of sodium with live hundred gramsof dry caustic soda are heated to about 400 to 500 cen- 8o tigrade in acast-iron vessel provided with a good stirring apparatus and being asfar as possible alkali-proof, and then the peroxid produced from fivekilos of sodium is slowly added while continually stirring. With violentreaction and strong heating the peroxid is reduced to oxid. After theperoxid has been added continue to heat for several hours and then leaveto cool. The reaction product is pulverized with exclusion of moisture eand then forms a reddish-yellow mass, this coloring probably arisingfrom traces of iron oxid. If this product should still contain peroxidor too much metallic sodium, which may be seen by dissolving in water,it may 5 eventually once more be heated.

The caustic soda may be omitted in the above example but in that casethe heating must be kept up for a longer time until the peroxid iscompletely reduced. The best I00 way to proceed in this. case is to takefrom five to ten per cent. more sodium for the reduction of the peroxidand toward the end of the operation to produce a vacuum in the vessel,so that the superfluous sodium is distilled off.

What I claim is-- 1. Aprocess forthe manufacture of sodium oXid, byheating peroXid of sodium with sodium, the heating being effected inoacuo dium with the addition of a small percentage of a caustic alkali.

5. A process for the manufacture of sodium oxid, by heating peroxid ofsodium with sodium with an addition of a small percentage of a causticalkali, up to a temperature exceeding 400 centigrade.

6. A process for the manufacture of sodium oxid, by heating peroxid ofsodium with sodium, with an addition of a small percentage of a causticalkali, up to a temperature exceeding 400 centigrade, the heating beingeffected in vacuo toward the end of the operation.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses.

AUGUSTUS BISCHLER.

Witnesses AMAND BITTER, ALBERT GRAELER.

